Metabolic studies of the corneal tissue using redox fluorometry and light scattering are proposed. Redox fluorometry is a non-invasive method whereby the fluorescence of reduced pyridine nucleotides and oxidized flavorproteins serves as an index of cullular redox state. Measurements of this fluorescence and the amount of the light scattering as a function corneal depth will be made. In addition, differences in metabolic state between individual cells within a single corneal layer will be measured. The measurements will be made in perfused corneas in vitro and in animals in vivo. The proposed experiments will focus on investigating the corneal metabolic changes which occur during reduced oxygen availability, wound healing, corneal storage, changes in endothelial or epithelial fluid pump rate and corneal disease. The non-invasive measurements will be correlated with histological and microstructural studies made on the same tissue. The possibility of applying the methods developed to clinical diagnosis and treatment will also be investigated.